There's one thing you have to think about for 6th sense.
How the opponent is fighting ?
If he get a long range weapon too, your 6th sens bonus can be cancelled (Whip/Other halleberd), very low (Bâton/Trident/Lance) .... to huge (couteau, saï, punch..)
For halleberd I love this weapon but I think than the 2 real requirements are Agilité du Félin or Implacable + Persévérant.
Whip by itself is in my opinion a better weapon.
With skills fitting and/or if the opponent get thief hallberd can outclass whip.
PS: Thanks for the datas Xteen. I'll update the database in the week. Still waiting for more datas to make a big update.